Detroit Pistons guard
An MRI exam Sunday confirmed the injury, which will require surgery. It's a huge blow for the Pistons, who'd rebounded after a terrible start to move into contention for a playoff spot in the East.
Jennings, 25, averaged 15.4 points and 6.6 assists in 41 games this season.
"It's definitely a tough loss for us," Pistons forward Greg Monroe said before Sunday night's game at Toronto. "He's a huge part of the success we've had recently."
The Pistons said there is no timetable for Jennings' return, but the guard tweeted a message earlier Sunday saying "6/9 months."
"Not being able to play basketball is the worst thing," Jennings tweeted in a separate message.
During Friday's Bulls-Mavericks telecast, ESPN commentator Jeff Van Gundy accused Bulls management of trying to undermine coach Tom Thibodeau by leaking disparaging stories, saying the practice dates to Phil Jackson's tenure as well as Scott Skiles' and Vinny Del Negro's.
Asked Sunday about Van Gundy's comments, management responded.
"Tom Thibodeau isn't being undermined at all," said John Paxson, executive vice president of basketball operations. "What's being undermined is the entire Bulls organization by Van Gundy, who has an agenda against our organization for whatever reason and has for years. I guess he thinks he's trying to protect his friend, but he's doing just the opposite. It's pretty pathetic when you think about it, and truth be told he owes Jerry Reinsdorf an apology for his disparaging remarks."